﻿using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
using System.Drawing;

namespace UIBParser
{
    public class ExtendedDataGridView : DataGridView
    {
        /// <summary>
        /// this method overrides the DataGridView's RowPostPaint event 
        /// in order to automatically draw numbers on the row header cells
        /// and to automatically adjust the width of the column containing
        /// the row header cells so that it can accommodate the new row
        /// numbers,
        /// </summary>
        protected override void OnRowPostPaint(DataGridViewRowPostPaintEventArgs e)
        { 
            //store a string representation of the row number in 'strRowNumber'
            string strRowNumber = (e.RowIndex).ToString();
            
            // TODO: Migrate to a more .net friendly implementation, e.g. string.Format()
            //prepend leading zeros to the string if necessary to improve
            //appearance. For example, if there are ten rows in the grid,
            //row seven will be numbered as "07" instead of "7". Similarly, if 
            //there are 100 rows in the grid, row seven will be numbered as "007".
            while (strRowNumber.Length < this.RowCount.ToString().Length)
            {
                strRowNumber = "0" + strRowNumber;
            }
            
            //determine the display size of the row number string using
            //the DataGridView's current font.
            SizeF size = e.Graphics.MeasureString(strRowNumber, this.Font);
            
            //adjust the width of the column that contains the row header cells 
            //if necessary
            if (this.RowHeadersWidth < (int)(size.Width + 20))
            {
                this.RowHeadersWidth = (int)(size.Width + 20);
            }
            
            //this brush will be used to draw the row number string on the
            //row header cell using the system's current ControlText color
            Brush b = SystemBrushes.ControlText;

            //draw the row number string on the current row header cell using
            //the brush defined above and the DataGridView's default font
            e.Graphics.DrawString(strRowNumber, this.Font, b, e.RowBounds.Location.X + 15, e.RowBounds.Location.Y + ((e.RowBounds.Height - size.Height) / 2));

            //call the base object's OnRowPostPaint method
            base.OnRowPostPaint(e);
        }
    }
}